A method for machining valve body castings

ABSTRACT

A and system for machining valve body castings, and the like, having inlet and outlet cored openings in opposite ends thereof, a valve seat, and a cored bonnet opening in the side thereof comprising: locating plugs movable into the inlet and outlet openings for positively locating the casting via the opposed cored openings a cutter for; machining the bonnet opening and/or seat of the positively located valve body; apparatus for removing the locating plugs; and mechanism for repositioning the valve body and positively locating on the machined bonnet opening and/or seat, and then machining the cored inlet and outlet openings or flange openings in opposite ends thereof.

United States Patent [191 Miles et al.

A METHOD FOR MACHINING VALVE BODY CASTINGS Inventors: Harry E. Miles;Dale W. Wright,

both of Saginaw, Mich.

Assignee: Miles Machinery Company,

- Saginaw, Mich.

Filed: Jan. 22, 1973 Appl. No.: 325,248

Related US. Application Data Division of Ser. No. 153,205, June 15,1971, Pat. No, 3,732,025,

US. Cl 408/42, 408/44, 408/61, 408/71, 408/103, 408/108, 29/563, 29/564Int. Cl B23b 39/20, B23b 39/22 Field of Search 408/36, 37, 38, 39, 40,408/41, 42, 43, 44, 56, 71, 31, 61, 79,103, 108; 10/106, 107 R; 90/14References Cited UNITED STATES PATENTS 8/1872 Gunn 408/38 397,311 2/1889Schoff 408/79 1,316,236 9/1919 Hoffman 408/56 1,616,150 2/1927 Teller etal. 408/41 2,953,069 9/1960 Smith 408/44 X 3,068,727 12/1962 Wertman408/36 1 Primary ExaminerGil Weidenfeld Attorney, Agent, or Firm-Learman& McCulloch [5 7 ABSTRACT A and system for machining valve bodycastings, and the like, having inlet and outlet cored openings inopposite ends thereof, a valve seat, and a cored bonnet opening in theside thereof comprising: locating plugs movable into the inlet andoutlet openings for positively locating the casting via the opposedcored openings a cutter for; machining the bonnet opening and/or seat ofthe positively located valve body; apparatus for removing the locatingplugs; and mechanismfor repositioning the valve body and positivelylocating on the machined bonnet opening and/or seat, and then machiningthe cored inlet and outlet openings or flange openings in opposite endsthereof.

12 Claims, 9 Drawing Figures PATENHU 31974 sum 1 or 4 FIGI Pmmgusar. menI ,3 ,3

SHEET 2 or 4 WENIH .88 31914 3.833312 SHEEI 30F 4 A METHOD FOR MACHININGVALVE BODY CASTINGS This is a division of application Ser. No. 153,205,filed in the United States Patent Office on June 15, 1971, now US. Pat.No. 3,732,025.

FIELD OF THE INVENTION This invention relates to machining systems andmore particularly to a new and improved apparatus for positivelylocating and machining valve bodies.

BACKGROUND OF THE INVENTION The machining of cast products, such asvalve bodies and other related castings, must be accomplished withspeed, efficiency, and accuracy. Accordingly, it is a primary object ofthe present invention to provide a machining system for accurately andefficiently machining valve body castings, and the like.

In valve body castings of the type disclosed herein having coredopenings in opposite ends, a valve seat, and a bonnet opening in theside thereof, the relative positions of the various finally machinedopenings is an important consideration in machining the parts.Accordingly, it is an object of the present invention to provide asystem for machining a valve body and the like wherein means is firstprovided for locating on the cored openings of a valve body to machinethe bonnet opening and mechanism is then provided for locating on themachined bonnet opening to machine the cored openings or flangeopenings.

In machining valve bodies, which include interior valve seats, theintroduction of coolant to the cutting tool machining an interiorportion of the valve, has presented a problem. Accordingly, it is afurther object of the present invention to provide new and novelapparatus having locating members which are employed for introducingliquid to a cutting tool interiorly of the side wall of a hollow valvebody to facilitate cutting.

Other objects and advantages of the present invention will becomeapparent as the description thereof proceeds.

THE SUMMARY OF THE INVENTION A system of machining cast valve bodies,and the like, having cored inlet and outlet openings at opposite endsthereof a cored bonnet opening, and a valve seat, the bonnet opening andvalve seat each having an axis generally perpendicular to the axis ofthe inlet and outlet openings comprising: locating apparatus includinglocating plugs insertable into the cored inlet and outlet openings, ascast, to accurately position the valve body on a support member;apparatus for machining the bonnet opening and/or seat while the valvebody is thus located; apparatus for removing the locating apparatus fromthe inlet and outlet openigs; apparatus for clamping the partiallymachined valve body on a locating member which is received in themachined bonnet opening or seat, and apparatus for machining the endportions of the valve body adjacent the cored inlet and outlet openingswhile locating on the machined bonnet opening or seat.

The present invention may more readily be described by reference to theaccompanying drawings in which:

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a top plan viewschematically illustrating a machining system constructed according tothe present invention;

FIG. 2 is a sectional, side view of a typical valve body which ismachined by apparatus constructed according to the present invention;

FIG. 3 is a fragmentary, side elevational view, taken along the line 33of FIG. 1, and particularly illustrating a valve body clamped to anindexible turntable and located for an initial machining operation bytapered locating plugs received in the inlet and outlet cored openings,as cast;

FIG. 4 is a sectional end view, taken along the line 44 of FIG. 3; I

FIG. 5 is a fragmentary, sectional plan view, particularly illustratingapparatus for machining the bonnet opening and valve seat at the firstmachining station; FIG. 6 is a fragmentary, sectional plan view,particularly illustrating apparatus at the second machining station forfinish boring the bonnet opening;

FIG. 7 is a fragmentary, sectional plan view illustrating apparatus forfacing the port flanges on the ends of the valve body;

FIG. 8 is a fragmentary, sectional plan view particularly illustratingapparatus for back-facing the port flanges on the ends of the valvebody; and

FIG. 9 is a side elevational view taken along theline 99 of FIG. 1, andparticularly illustrating the locating plug which is received in themachined bonnet opening of the valve body to locate the valve body whenport flanges are machined.

THE GENERAL DESCRIPTION Apparatus constructed according to the presentinvention is generally illustrated in FIG. 1 and includes bonnet openingmachining apparatus, generally designated A, which locates on the coredopenings 12 in opposite ends of a cast valve body 10 and machines thebonnet opening 16 (FIG. 2) of a valve body 10, and machining apparatus Bfor machining the cored end openings 12 while locating on the alreadymachined bonnet opening 16.

THE DESCRIPTION OF THE PREFERRED EMBODIMENT Apparatus constructedaccording to the present invention is particularly well suited formachining a rough casting, such as the valve body, generally illustratedat 10 in FIG. 2, having a pair of longitudinally ex tending, non-axiallyaligned cored passages or openings 11 therein terminating in inlet andoutlet ports 12 at opposite ends of the casting 10. The passages 11communicate with each other through a valve seat opening 14 in theinterior of the body 10. Perimetrical port flanges 13 are provided onopposite ends of the casting 10 for mounting the valve body to conduitsand the like (not shown). A single support lug 15, (FIGS. 2, 3 and 4) onthe underside of the rear portion of the body 10, and pairs of supportor locating lugs 17 (FIGS. 3 and 4) on the upper and lower sides of thefront portion of the body 10 are integrally cast on the body 10 for apurpose to be described more fully hereinafter.

A bonnet opening, generally designated 16, 'is cast into the side of thevalve body 10in communication with one of the axial passages l 1 and ingenerally radial alignment with the valve seat opening 14. A bonnetflange 18 is integrally cast with the body for mounting a valve bonnet(not shown) which mounts a valve stem (not shown) and a valve (notshown) as usual.

The valve body 10 is initially supported by an indexible turntable,generally designated 20, which is indexibly mounted on a support frame Fto sequentially position the valve body 10 at a plurality ofcircumferentially spaced work stations, generally designated 22, 24, 26and 28. The turntable 20 includes a vertical support post 21 which isrotatably supported on the frame F and is turned about its axis by asuitable source of power such as an electric motor (not shown) andoperates via suitable geneva mechanisms, for instance, to index theworkpiece.

As is best illustrated in FIGS. 3 and 4, the body 10 is supported by afixture F provided on the turntable 20. The fixture F includes avertical post 29 which is received in an opening 200 in the turntable.Level equalizing apparatus is supported on the post 29 for horizontalmovement and includes tapered support surfaces 31 on a freely slidableplate 29a in bearing engagement with complementally tapered guidesurfaces 32a on the undersides of supporting bar members 32 which mounta pair of front rest pads 33. A single rear rest pad 34 is also providedon fixture F but is not a locating pad, since, as later will appear,when the workpiece 10 is clamped, it is lifted off the pad 34.Horizontal outward movement of the parallel bars 32 is prevented by anenclosure wall 35 which is supported on thetable 20 and encases the barmembers 32 that are in vertical sliding engagement therewith. Asillustrated in FIGS. 3 and 4, the single, rear rest pad 34 is elevatedslightly above the front pads 33 to engage the lug 15. Pads 33 engagelugs 17 on the underside of the body 10 when the workpiece is clamped.By permitting relatively vertical movement of the pads 33 and 34, whenclamping occurs, the valve body 10 is oriented about the axis y to allowfor as cast variations in the valve body. 9

For properly locating the valve body 10 in conjunction with the locatingpads 33 and 34, a pair of locating slides 30 comprising a portion offixture assembly F are slidably mounted on the turntable 20 and includeintegrally formed dependent nuts having oppositely threaded bores 42therethrough for receiving a screw 44 having oppositely threaded ends44a and 44b for moving the locating slides 30 simultaneously, inopposite directions, toward and away from each other when the hand-wheel45 attached to one end of the screw 44 is turned. Each of the locatingslides 30 has a bore 46 therein receiving a bushing 48 in which the stem49 of a tapered locating plug 50 is. slidably received. An adjustmentbolt 52 is received in an apertured end'cap 54 and is threaded into thestem 49 to axially adjust each plug 50 relative to the slide 30. A fluidcommunicating passage'56 is provided in each locating plug 50 and is incommunication with a source 58 of cooling or cutting fluid for a purposeto be described more particularly hereinafter.

To assist in locating and clamping the valve body 10 on the turntable20, fixture F also includes a hydraulically operated clamping head 60pivotally mounted on a horizontal shaft 62, suitably supported on theturntable for pivotal movement between the solid line positionillustrated in FIG. 4, and the chain line position, partly illustratedin FIG. 4. At its forward end, the clamping head 60 mounts a cross beam64 having a pair of clamp pads 66 depending therefrom for engaging theas cast lugs 17 on the upper surface of the valve body 10. Beam 64 isrockably mounted on shaft 64a. The integrally cast lugs need not bemachined to provide precise clamping surfaces.

A pair of links 68 and 70, pivotally connected with the pivot pins 71and 72 fixed to the head 60 and turntable 20, respectively, arepivotally connected to each other by a pivot pin 73 and are movablebetween the solid and chain line positions illustrated in FIG. 4, bymeans of the piston rod 75 of a solenoid actuated, fluid operatedcylinder 76 which is pivotally mounted on the turntable by a pivot pin77. The valve body 10 is clamped to the indexing'tumtable 20 in aposition rotated 90 about its longitudinal axis x from the position inwhich it is illustrated in FIG. 2.

Surrounding the turntable 20 are a plurality of power-operated machininghead assemblies 82, 84, 86 and 88 at the work stations 22, 24, 26 and 28respectively, which may be of the general character described in US.Pat. No. 2,915,924 granted Dec. 8, 1959, for example. Alternatively,each of the machining assemblies 82, 84, 86 and 88 may comprise a heavyduty slide feed unit, such as that manufactured by Miles MachineryCorporation of Saginaw, Michigan, which features easily adjustablecontrols for rapid advance, variable feed and rapid return cycles. Ineither case, each of these heads includes a rotary spindle S which maybe rapid traversed to and from machining position fed in a machiningpass in the usual manner. The machining apparatus 82 includes a toolsupporting body, illustrated generally at 78 (FIG. 5) supported on ahorizontally movable slide 89, mounted on its machining assembly spindleS, and having, at its axially outer end, a valve seat machining toolsystem 79 and, at an axially inner portion thereof, a bonnet openingmachining tool system 80. The valve seat machining system 78 includes aboring tool 81 for rough boring the surface a in the valve seat opening14 and a counterboring tool 83 for rough counterboring surface b.

The bonnet opening tool system includes boring and counterboring tools85 and 87 for rough boring and rough counterboringthe surfaces 0 and drespectively in the bonnet opening '16. A facing tool 87a is mounted onthe slide 89. Conventional apparatus (not shown) is provided for movingthe slide 89 and the facing tool 87a radially relative to the bonnetopening 16 to face the surface e of the bonnet flange 18. A guide track90 is provided on the slide 89 and receives a guide 91 on the spindle Sof the machining apparatus 82 for guiding the radial movement of theslide 89.

It is important to note that when the valve seat opening 14 is beingbored and counterbored, cooling or cutting fluid is supplied through theports 56 in the locating plugs 50 through the valve body passages 11 tothe surfaces a and b being machined.

The machining head 84, at the second machining station 24, comprises afinish boring and counterboring tool system including a head 94 havingaxially spaced boring tools 92 and 93 for more finish boring andcounterboring respectively, of the surfaces 0 and d. Apparatus,generally designated 84a, is provided for moving the head 94 axiallytoward and away from a valve body casting 10 on the turntable 20.

The conventional machining tool assembly 86, at the downstream workstation 26, includes a plurality of circumferentially spaced rotarydrills 95 which drill bores 96 through the valve body bonnet flange 18.The individually rotated drills are carried by a common drill head 96a(FIG. 1) on the assembly spindle S and conventional mechanism isprovided for driving the drills individually. This may comprise aconventional gear box mechanism for translating rotation of spindle S toindividual rotation of each drill 95.

At the fourth work station 28, the machining head mechanism 88 includesa plurality of circumferentially spaced taps 97, which tap the holes 96in the bonnet flange 18. The tapping head mounting the tapping units 97is of the same general construction as the drilling head. The taps arealso individually driven from the spindle S, and the spindle S isreversible to back out the taps.

The apparatus, generally designated B, in FIG. 1, for machining the portflanges 13, includes a turntable 100 mounted on a vertical post 102which is rotatably mounted on a second frame or base C and is adapted toreceive the partially machined valve body 10. Apparatus (not shown) isprovided for rotating the post 102 about its axis to move the valve bodymounted thereon between a plurality of circumferentially spaced apartwork stations, generally designated 104, 105, 106 and 107. The turntable100, which may be indexed in the same manner as turntable 20, includesan annular flange 103 rotatably journaled by a frame supported annularguide rib 104. Mounted atop the table 100, by locating pins 100a, is afixture base 110 having a locating plug assembly, generally designated112, centered thereon. The locating plug assembly 112 comprises acylindrically shaped arbor 114 having a central bore 115 therethroughfor receiving a bolt 116 which is threaded into the fixture base 110.Received on the arbor 114 is a plug collar, generally designated 118,including an annular base portion 120 fixed to the arbor 114 by screws121 and a flange 119 receivable in the already machined bonnet opening16. The screws 121 removably couple the collar 118 to the arbor 114. Aplurality of rest buttons 122 are provided on the base 120 forsupporting the bonnet flange 18 of a valve body 10 mounted on thecentering plug 112. To properly orient the valve body 10 on thecentering plug 112, a valve body orienting button 123 is provided on thebase 120 and is adapted to be received in one of the threaded holes 96provided in the bonnet flange 18. As illustrated in FIG. 9, the annularplug 119 is snugly received by the finished surface 0 of the bonnetopening 16 to precisely position the valve body 10 on the turntable 100.

For clamping a valve body 10 to the fixture base 110, a clamping bar 130is provided and is supported at one end 130a on the upper end of athreaded post 128 mounted on the fixture base 110. A pair of nuts 129,threaded on the post 128, generally determine the vertical position ofthe end 130a of the bar 130. The end 130a of the bar 130 includes anenlarged bore 130b freely receiving the post 128 so as to permit limitedswinging movement of the bar 130 in a vertical path, designated by thearrow m (FIG. 9). An expansion spring 129a is provided between the lowernut 129 and the bar 130 to constantly, but yieldably, urge the bar 130to the position illustrated in the drawing.

To vertically swing the bar 130 in the direction of the arrow m, againstthe biasing force of spring 129a, between clamping and unclampingpositions, a double acting, solenoid actuated, fluid operated cylinder127 is supported on the base and includes a piston rod 126 fixed to theend 1300 of the bar 130. A work engaging button 131 is provided on theunderside of the bar for engaging the support lug 15 on the'valve body10 when the bar 130 is lowered to the clamping position illustrated inthe drawing.

A plurality of machining tool assemblies, generally designated 134, 135,136 and 137 and of the construction previously mentioned, is provided atwork stations 104, 105, 106 and 107, respectively. The machining toolassembly 134 comprises a facing tool 140 (FIG. 7) mounted on a slide 141which is axially and transversely movable for facing the surface h ofone of the port flanges 13. The slide 141 is mounted on the spindle S ofhead assembly 134. V

The machining apparatus 135, at station 105, comprises a back facingtool 142 for facing the back surface i of the port flange 13. Tool 142is mounted on the spindle S of machining head 135.

The machining apparatus 136, at the station 106, comprises a pluralityof drills 144 for drilling holes 145 in the port flanges 13. Thedrills144 are mounted on a drill plate 144a on the spindle S of machininghead136 for individual rotation in the manner previously designated.

The machining apparatus'137 comprises a plurality of taps 146 fortapping the drilled holes 145 in the flange 13. The taps are mounted forindividual rotation on a tapping head 146a mounted on the spindle S ofmachining head 137. It should be realized, of course, that the machiningassemblies 134 and 136 can operate simultaneously, and that themachining assemblies 137 and 135 can also operate simultaneously, tosimultaneously machine opposite end flanges 13 of the body 10. Each ofthe machining assemblies 134, 135, 136 and 137 is equipped with aheavy-duty slide feed unit which features easily adjustable controls forrapid advance, variable feed, and rapid return cycles.

Because the bonnet flanges 13 on the valve bodies 10 are symmetrical, itis possible to utilize machining apparatus 82 to also face and drill thebonnet flanges 13. Because the valve bodies 10 are stationarily mountedon the indexing tables 20 and 100 and the various tools rotate tomachine the valve body, the need for cumbersome rotating fixtures hasbeen eliminated and a greater rigidity is possible, permitting greaterprecision in machining. As is evidenced from the description, thepresent system also allows a number of operations to be performed,either simultaneously or sequentially, with a single chucking of theworkpiece. By minimizing the number of times the part is handled,productivity 'is increased and machining quality is improved. It hasbeen found that, with apparatus constructed according to the presentinvention, valve body castings of the type described can be completelymachined at an average rate of 7.5 parts per hour with only oneoperator. Control valve bodies ranging from /2 inch through 6 inch sizeshave been satisfactorily machined with apparatus constructed accordingto the present invention. This apparatus permits fast changeover fromone size or variety of valve body to another, thereby permitting optimumproductivity. Gate valve bodies may also be machined utilizing. theprinciples and concepts of the present invention.

THE OPERATION A rough valve body casting 10 is initially placed on thesupport pads 33 and 34 provided on the turntable 20. The tapered plugs50 are then inserted into the cored ports 12 via hand-wheel 45 to locatethe body 10 and lift the body 10 off the pad 34. Immediately afterlocating has been accomplished, the clamping head 60 is operated toclamp the valve body in position. Upon clamping, the valve body 10rotates slightly about the longitudinal axis thereof to raise the lug lslightly off the rest pad 34, and return the lowermost front lugs 17into engagement with the pad 33. The locating pads 33 are relativelyvertically movable to accommodate to the particular valve body as cast.The valve body to be machined is then indexed to a position opposite theboring head 78, at station 82, where the bonnet opening 16 and the valveseat opening 14 are rough bored, rough counterbored and faced. The tableis then indexed to the station 84 where the surfaces a and b are finishbored and counterbored with the finishing tools 92 and 93. When thevalve opening is being bored, counterbored and finish bored, cuttingfluid is passed through the passages 56 through the locating plugs tofacilitate cutting and to cool the cutting tools 81, 79, and 87.

The table 10 is then indexed to move the valve body 10 to a positionopposite the drills 95 for multiple drilling of the port flange 13, andthen' is finally indexed to a position opposite the taps 97 where thedrilled holes 145 are tapped. When the taps 97 have been backed out, theoperator releases the hydraulic clamp 60, unloads the valve body fromthe turntable l0, and loads it on the other turntable 100.

The valve body 10 is positioned on the turntable 100 with plug 119snugly received by the surface 0 of the bonnet opening 16. Thehydraulically operated clamping cylinder 127 is then actuated to movethe clamping bar 130 into clamping engagement with the valve body 10.

The turntable 100 may then be indexed so that the valve body 10 ispositioned opposite the head 134 at the station 104 where one of theflanges 13 is backfaced while the opposite flange 13 is multiple drilledat station 106 by the drills 144. The turntable 100 is then indexed 90and the back-faced flange is step-faced at station 105, while thedrilled flange is tapped at station 107. The turntable 100 is againindexed 90 and the faced flange is drilled at station 100 while theopposite flange is back-faced at station 104. The table 100 is thenindexed to the final position where the just drilled holes are tapped atstation 107, and the flange on the opposite end is step-faced.

if the valve body 10 does not include port flanges l3 and the ports 12are to be drilled and tapped, the machining apparatus and cycle isslightly different. The combination tool at the first station 104wouldcomprise drilling and facing apparatus for drilling and plungefacing one of the openings 12. The table 100 would then be indexed sothat the opposite port 12 is drilled and faced. The table 100 is thenindexed 90 to present the first opening to a tapping apparatus providedat station 105. The table 100 is then finally rotated 180 to present theopposite port 12 to the tapping apparatus at station 105 to tap theopposite port 12.

trated version of the valve body. The machining cycles of the apparatusillustrated in FIG. 1 is completely automatic so that one operator isable to unload and reload valve bodies from and onto the table 12 whilethe table 100 is indexing in a machining cycle and vice versa.

It should be understood that any reference to the machining of portionsof the valve body adjacent the ports may interchangeably refer to eitherthe flanges 13 in the illustrated version of the valve body or to theportion of the valve defining the ports 12 in the second version. Also,it should be understood that expandable arbors could be substituted forthe plugs 50, if desired.

It should also be understood that the plugs 50 could also be insertedaxially inwardly of the outer portions of ports 12 so as to locate onthe valve seat openings in a gate valve body which are axially alignedwith the outer portions of inlet and outlet openings 12 and may beconsidered to comprise portions thereof.

It is to be understood that the drawings and descriptive matter are inall cases to be interpreted as merely illustrative of the principles ofthe invention, rather than as limiting the same in any way, since it iscontemplated that various changes may be made in various elements toachieve like results without departing from the spirit of the inventionor the scope of the appended claims.

I claim:

1. A system for machining a valve body casting, having cored inlet andoutlet openings at opposite ends thereof and a cored bonnet opening inthe side thereof comprising:

indexible means for supporting a valve body to be machined; locatingmeans including first plug means receivable in said inlet and outletopenings as cast, for positively locating said valve body on saidindexible means;

first machining means disposed adjacent said indexible means andincluding rotatable cutting tool means movable toward and away from thelocated valve body to machine said bonnet opening;

means for removing said first plug means from said valve body;

additional plug means of such size and shape as to be snugly receivablein the machined bonnet opening for positively relocating the valve body;and second machining means including rotatable cutting means movabletoward and away from said additional plug means and said valve body, formachining opposite end portions of said valve body adjacent said inletand outlet openings when said addi-. tional plug means is received insaid bonnet opening. 7 I

2. The system set forth in claim 1 wherein said first machining means isoperative to also machine a valve seat interiorly of said valve body;said first plug means having fluid communicating passages therein forintroducing fluid through said cored inlet and outlet openings tofacilitate machining of said valve seat by said first machining means.

3. The system set forth in claim 1 wherein said valve body has upper andlower, axially spaced, integrally cast clamping lugs; and clamping meanshaving upper and lower pairs of axially spaced clamping membersengageable with said upper and lower clamping lugs respectively forclamping said casting to said support means and preventing its rotationwhen said bonnet opening is machined; the clamping members of each pairof said upper and lower clamping members being movable verticallyrelative to each other to allow for casting variations in the valvebody.

4. The system set forth in claim 3 wherein said indexible means includesrest pad means for initially supporting the side of said valve bodyopposite said bonnet 1 opening when said first plug means is received insaid inlet and outlet openings, said clamping means being operative toturn said valve body about its axis slightly to raise said opposite sideof said valve body off said rest pad means to a raised position in whichit is machined by said first machining means.

5. The apparatus set forth in claim 1 wherein said first machining meanscomprises a plurality of circumferentially spaced machining members atspaced machining stations; and said indexible means comprises arotatable turntable means for sequentially positioning said valve bodyat said machining stations.

6. The apparatus set forth in claim 1 wherein said valve body includes abonnet flange adjacent said bonnet opening; and said first machiningmeans comprises means at a first machining station for rough boring andrough counterboring said bonnet opening; and means for facing saidbonnet flange.

7. The apparatus set forth in claim 6 wherein said indexible meanscomprises rotatable turntable means; said first machining means includesmeans at a second machining station circumferentially spaced downstreamof said first station for finish boring and finish counter boring saidbonnet opening.

8. The apparatus set forth in claim 7 wherein said first machining meansincludes drilling means, at a third station downstream of said secondstation, for drilling openings in said flange; and tap means, at afourth station downstream of said third station, for tapping saiddrilled openings.

9. The apparatus set forth in claim 8 wherein said casting includesmounting flanges adjacent said inlet and outlet openings; said secondmachining means comprising means at a fifth station for facing theaxially inner faces of at least one of said mounting flanges, and meansat a sixth station, downstream of said fifth station, for facing theaxially outer face of said one flange.

10. The apparatus set forth in claim 8 wherein said second machiningmeans comprises means at a fifth station for core drilling and plungefacing said inlet and outlet openings, and means at a sixth stationdownstream from said fifth station for tapping said drilled 10 openings.

11. A system for machining a valve body casting, or the like, havinginlet and outlet openings at opposite ends thereof and a bonnet openingin the side thereof, and a valve seat adjacent said bonnet opening andat least one of said inlet and outlet openings comprising:

a table for supporting a valve body to be machined;

means for clamping said valve body to said table;

machining means disposed adjacent the table and including rotatablecutting tool means movable, toward and away from said table and a valvebody supported thereon, between remote and operative positions tointeriorly machine a valve seat adjacent said bonnet opening andadjacent at least one of said inlet and outlet openings;

said clamping means comprising plug means receivable in said inlet andoutlet openings, as cast, for locating said body when it is beingmachined, and means for introducing fluid through said plug means tofacilitate the machining of saidvalve seat interiorly of said valvebody.

12. A system formachining a workpiece such as a valve body casting,having a cored opening comprising inlet and outlet portions at oppositeends thereof and an additional portion having an axis generallyperpendicular to the axes of the inlet and outlet portions comprising:

indexible means for supporting a workpiece to be machined;

locating means, receivable'on locating surfaces in said opening as cast,for positively locating said workpiece on said indexible means; firstmachining means disposed adjacent said indexible means and includingrotatable cutting tool means movable toward and away from the locatedvalve body to machine said additional portion;

means for removing said locating means from said valve body;

additional locating means so dimensioned as to be receivable in themachined additional portion for positively relocating the workpiece; and

second machining means including rotatable cutting means movable towardand away from said additional locating means and said workpiece formachining said inlet and outlet portions of said workpiece when saidadditional locating means is received in said additional portion. 1

1. A system for machining a valve body casting, having cored inlet andoutlet openings at opposite ends thereof and a cored bonnet opening inthe side thereof comprising: indexible means for supporting a valve bodyto be machined; locating means including first plug means receivable insaid inlet and outlet openings as cast, for positively locating saidvalve body on said indexible means; first machining means disposedadjacent said indexible means and including rotatable cutting tool meansmovable toward and away from the located valve body to machine saidbonnet opening; means for removing said first plug means from said valvebody; additional plug means of such size and shape as to be snuglyreceivable in the machined bonnet opening for positively relocating thevalve body; and second machining means including rotatable cutting meansmovable toward and away from said additional plug means and said valvebody, for machining opposite end portions of said valve body adjacentsaid inlet and outlet openings when said additional plug means isreceived in said bonnet opening.
 2. The system set forth in claim 1wherein said first machining means is operative to also machine a valveseat interiorly of said valve body; said first plug means having fluidcommunicating passages therein for introducing fluid through said coredinlet and outlet openings to facilitate machining of said valve seat bysaid first machining means.
 3. The system set forth in claim 1 whereinsaid valve body has upper and lower, axially spaced, integrally castclamping lugs; and clamping means having upper and lower pairs ofaxially spaced clamping members engageable with said upper and lowerclamping lugs respectively for clamping said casting to said supportmeans and preventing its rotation when said bonnet opening is machined;the clamping members of each pair of said upper and lower clampingmembers being movable vertically relative to each other to allow forcasting variations in the valve body.
 4. The system set forth in claim 3wherein said indexible means includes rest pad means for initiallysupporting the side of said valve body opposite said bonnet opening whensaid first plug means is received in said inlet and outlet openings,said clamping means being operative to turn said valve body about itsaxis slightly to raise said opposite side of said valve body off saidrest pad means to a raised position in which it is machined by saidfirst machining means.
 5. The apparatus set forth in claim 1 whereinsaid first machining means comprises a plurality of circumferentiallyspaced machining members at spaced machining stations; and saidindexible means comprises a rotatable turntable means for sequentiallypositioning said valve body at said machining stations.
 6. The apparatusset forth in claim 1 wherein said valve body includes a bonnet flangeadjacent said bonnet opening; and said first machining means comprisesmeans at a first machining station for rough boring and roughcounterboring said bonnet opening; and means for facing said bonnetflange.
 7. The apparatus set forth in claim 6 wherein said indexiblemeans comprises rotatable turntable means; said first machining meansincludes means at a second machining station circumferentially spaceddownstream of said first station for finish boring and finish counterboring said bonnet opening.
 8. The apparatus set forth in claim 7wherein said first machining means includes drilling means, at a thirdstation downstream of said second station, for drilling openings in saidflange; and tap means, at a fourth station downstream of said thirdstation, for tapping said drilled openings.
 9. The apparatus set forthin claim 8 wherein said casting includes mounting flanges adjacent saidinlet and outlet openings; said second machining means comprising meansat a fifth station for facing the axially inner faces of at least one ofsaid mounting flanges, and means at a sixth station, downstream of saidfifth station, for facing the axially outer face of said one flange. 10.The apparatus set forth in claim 8 wherein said second machining meanscomprises means at a fifth station for core drilling and plunge facingsaid inlet and outlet openings, and means at a sixth station downstreamfrom said fifth station for tapping said drilled openings.
 11. A systemfor machining a valve body casting, or the like, having inlet and outletopenings at opposite ends thereof and a bonnet opening in the sidethereof, and a valve seat adjacent said bonnet opening and at least oneof said inlet and outlet openings comprising: a table for supporting avalve body to be machined; means for clamping said valve body to saidtable; machining means disposed adjacent the table and includingrotatable cutting tool means movable, toward and away from said tableand a valve body supported thereon, between remote and operativepositions to interiorly machine a valve seat adjacent said bonnetopening and adjacent at least one of said inlet and outlet openings;said clamping means comprising plug means receivable in said inlet andoutlet openings, as cast, for locating said body when it is beingmachined, and means for introducing fluid throuGh said plug means tofacilitate the machining of said valve seat interiorly of said valvebody.
 12. A system for machining a workpiece such as a valve bodycasting, having a cored opening comprising inlet and outlet portions atopposite ends thereof and an additional portion having an axis generallyperpendicular to the axes of the inlet and outlet portions comprising:indexible means for supporting a workpiece to be machined; locatingmeans, receivable on locating surfaces in said opening as cast, forpositively locating said workpiece on said indexible means; firstmachining means disposed adjacent said indexible means and includingrotatable cutting tool means movable toward and away from the locatedvalve body to machine said additional portion; means for removing saidlocating means from said valve body; additional locating means sodimensioned as to be receivable in the machined additional portion forpositively relocating the workpiece; and second machining meansincluding rotatable cutting means movable toward and away from saidadditional locating means and said workpiece for machining said inletand outlet portions of said workpiece when said additional locatingmeans is received in said additional portion.